Wow, there are many great suggestions above:
1. Radio Tuner (Better yet: World Band Radio or XM Satellite Radio)
2. QT Management System: Audio (mp3), Video (.mov from iMovie)
3. 8-bit Display: Play Movies, Games, iTunes Surreal interface
4. Games: Pong, Chess,
5. Wireless: Ability to add Airport Card or Bluetooth, etc.
6. Voice Recording: (inc Optional Add on Mic)
7. Faster and Bigger Drive (They get smaller and faster and cheaper) to handle apps
8. Email & Instant...